Systematic evaluation of the immunological, neurological, gastrointestinal, and hepatic toxicity of glyoxal in food

Glyoxal dietary exposure caused multi-organ toxicity in zebrafish larvae. • MNLC (2.37 μL/mL) and LC10 (5.60 μL/mL) of glyoxal were defined in zebrafish. • Glyoxal at LC10 impaired innate and adaptive immune cell populations. • Glyoxal triggered CNS apoptosis, liver enlargement, and hepatic lesions. Glyoxal is a reactive dicarbonyl compound that is widely detected in carbohydrate- and lipid-rich foods; however, its systemic toxicological effects remain incompletely characterized. Therefore, this study employed wild-type and transgenic zebrafish models to evaluate the systemic toxicity of glyoxal, determining its maximum non-lethal concentration (MNLC) and 10% lethal concentration (LC 10 ). The immunological, neurological, gastrointestinal, and hepatic toxicities of glyoxal at different concentrations were systematically evaluated. Acute toxicity analysis showed that the MNLC of glyoxal was 40.84 mM, and the LC10 was 96.49 mM. Glyoxal produced endpoint-specific toxic effects rather than a uniform continuous dose-response pattern. At the LC 10 concentration, glyoxal significantly reduced neutrophil abundance, T-cell-associated fluorescence, and macrophage-associated fluorescence; decreased gastrointestinal area; increased liver area and residual yolk-sac area; and induced marked hepatic pathological alterations. At the MNLC concentration, glyoxal significantly reduced macrophage-associated fluorescence and increased residual yolk-sac area. Increased residual yolk-sac area was also observed at 1/3 MNLC. In the nervous system, increased central nervous system apoptosis was detected at selected concentrations, whereas no significant changes were observed in motor-neuron development or locomotor distance. Glyoxal also had no significant effect on gastrointestinal neutrophil density or mean liver brightness. Collectively, these findings indicate that the toxicity of glyoxal is characterized by organ- and endpoint-specific threshold-like responses, with most overt toxic effects occurring at or near the LC 10 concentration. This study provides experimental evidence for the hazard characterization of glyoxal and supports further investigation of its relevance to food-safety risk assessment. Download: Download high-res image (245KB) Download: Download full-size image